Benzimidazole compounds and pesticidal preparations containing them

ABSTRACT

1. A BENZIMIDAZOLE COMPOUND OF THE FORMULA   1-(R4-S-CO-),2-R3,5-R1,6-R2-BENZIMIDAZOLE   WHEREIN R1, AND R2 MAY BE IDENTICAL OR DIFFERENT AND ARE HYDROGEN, HALOGEN, LOWER ALKYL, NITRO OR TRIFLUOROMETHYL, R3 IS HYDROGEN, LOWER ALKYL OR CYCLOALKYL OF 3 TO 6 CARBON ATOMS, AND R4 IS LOWER ALKYL, PHENYL, PHENYL MONO- OR DISUBSTITUTED BY HALOGEN, LOWER ALKYL OF NITRO, OR BENZYL.

United States Patent US. Cl. 260309.2 4 Claims ABSTRACT OF THE DISCLOSURE The invention relates to benzimidazole derivatives of the general formula wherein R and R may be identical or diiferent and each represents hydrogen, halogen, alkyl, alkoxy, alkylthio, NO CN, or CF R represents hydrogen or an alkyl or cycloalkyl residue, and R represents an alkyl, aralkyl or aromatic residue.

These new compounds are very effective as ingredients in biocidal preparations for plant-protection and combating fungi, insects, acarides, nematodes, endoparasites and microbes.

CROSS-REFERENCE This application is a continuation-in-part of our application Ser. No. 769,699 filed Oct. 22, 1968, new US. Pat. No. 3,652,580.

The present invention provides compounds of the general formula wherein R and R may be identical or difierent and each represents hydrogen, halogen, alkyl, alkoxy, alkylthio, NO CN, or CF R represents hydrogen, or an alkyl or cycloalkyl residue, and R represents an alkyl, aralkyl or aromatic residue.

The present invention also provides a pesticidal preparation which comprises, as active ingredient, at least one ice compound of the general formula I given above, together with a suitable carrier.

The preparation may contain one or more of the following additives: a solvent, a diluent, an emulsifier, a dispersing agent, a thickener, an adhesive as well as other known pesticides.

The active substances defined by formula I possess various interesting biocidal properties. They not only act as herbicides and defoliants, but at lower concentrations, at which no phytotoxic side eflects arise, they show a strong lethal action on various representatives of the order acarina (ticks, spider mites and the like), insects and soil insects, their eggs and larvae, storage pests, for example cockroaches, snails and their eggs, nematodes, plantpathogenic and human-pathogenic fungi, bacteria and viruses, animal-pathogenic and human pathogenic worms and spirochetes.

The symbol R in the general formula of this invention is defined as hydrogen or an alkyl or cycloalkyl residue. The alkyl residue may be branched, straight chained and preferably represents a lower alkyl residue like methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec.buty1 or tert.butyl. Perhalogenated aliphatic residues are excluded by this definition. Possible cycloalkyl residues are, for example, the cyclopropyl, cyclo'butyl, cyclopentyl or cyclohexyl residue.

R in the general formula in this invention is defined as an alkyl, aralkyl or aromatic residue; the aromatic residue, preferably phenyl, may be substituted in the most diverse manner, for example, by halogen atoms, or alkyl, alkoxy or alkylthio residues, or by the groups NO CN, CF and the like. If R, is an alkyl residue, it preferably represents lower alkyl residues with 1 to 4 carbon atoms. The aralkyl residues are benzyl and phenylethyl which may be substituted in the phenyl ring.

The new compounds of this invention which are especially distinguished by their herbicidal and fungicidal and ovicidal action correspond to the formula wherein R is hydrogen or chlorine, a --NO CH or CF R is hydrogen or chlorine,

R is hydrogen, a lower alkyl group of 1 to 4 carbon atoms or the cyclopropyl residue,

R is a lower alkyl group with 1 to 4 carbon atoms, a

phenyl ring that is unsubstituted or monoor disubstituted by chlorine, methyl or NO or R is the 'benzyl radical.

Examples of such compounds are the following:

R1 Ra R4 H H H 00115 H H H 00113012 (3,4) H H H CsH cH (111.) H H H OH;

H H H 02115 H H H CaHr H H CH3 CH1:

H H CH3 CH H H CH3 C3111 Cl H H CuHsClz (3,4) Cl H H CaHrCHs (111.) Cl H H C2H5 Cl H H 03117 01 H CH: CsHsCh (3,4) or H CH3 0511,0113 (m.) 01 H CH1; 02115 N02 H H CaHaClz (3,4) NO: H H GBH4CH3 (m.) N02 H H C2H5 N0 H CH3 CeHsClz (3,4) N01 H CH3 CtlHqCHg N02 H CH3 C2115 CH; H H 00113012 (3, 4) CH3 H H CsH CH OH; H H C2 OH; H H CaH1 CH3 H CH3 COH3012 (3, 4) CH H CH: C5H4CH3 (1a.) CH H CH3 2H5 CH3 H CH3 caH'l CFa H H CaH5 CFs H H CuHaClz (3, 4) CF; H H COH4CH3 (111.) Ch H H CH3 CF: H CH3 CsHs O H CH3 CsHaCh (3, 4) CF; H CH3 COH4CH3 (111.) CF; H CH3 C2115 OF; H CH3 CsH7 H H Cyclopropyl C 11 N02 H Cyelopropyl C5Hs OH; H Cyelopropyl CsHs N02 H Cyclopropyl CH;

CH: H Cyclopropyl CH,

01 H Cyclopropyl CeHa Cl H Cyclopropyl CsHsClz (3, 4) 01 H Cyelopropyl C6H4CH (111.) 01 H Cyclopropyl 02115 01 H Cyclopropyl 03117 (n.)

Cl H Cyclopropyl 03111 (i.)

01- H Cyclopropyl OaH4NO2 (11.) Cl H Cyclopropyl 04110 (11.)

Cl H Cyclopropyl Benzyl Cl 1 Cl Gyclopropyl CH Cl ()1 Cyclopropyl CsHs Cl Cl Cyclopropyl Benzyl The active substances of formula I represent benzimidazolyl derivative of formula I cording to the methods usual for the preparation of this class of substances.

As a rule, the procedure followed is to react a benzimidozolyl derivative of formula C-Ra R N III with a compound of formula 3R IV wherein A and B are groups which are able to form the grouping whilst undergoing elimination or condensation.

In general, the procedure followed will be to react, in optional sequence, a reactive derivative of thiocarbonic acid with an imidazole of formula III (A=H) and an alcohol or phenol of formula IV (B=OH).

The procedure followed for the formation of urethanes is to react an imidazole of formula III with the desired chlorothiocarbonate.

The new preparations can be applied in many different forms, for example, in the form of sprays, dusting powders and granules. They can also be worked directly into the soil, optionally together with fertilisers.

Possible materials for the manufacture of directly sprayable solutions of the compounds of general formula I are, for example: mineral oil fractions of high to medium boiling range, for example, Diesel oil or kerosene, coal tar oil and oils of vegetable or animal origin, as well as hydrocarbons, for example, alkylated naphthalenes, or tetrahydronaphthalene, optionally using xylene mixtures, cyclohexanols, ketones, and furthermore chlorinated hy drocarbons, for example, trichlorethane and tetrachlorethane, trichlorethylene or trichlorobenzenes and tetrachlorobenzenes. It is advantageous to use organic solvents having boiling points above C.

It is especially appropriate to prepare aqueous forms for application from emulsion concentrates, pastes or wettable spraying powder by adding water. Possible emulsifiers or dispersing agents are non-ionic products, for example, condensation products of aliphatic alcohols, amines or carboxylic acids having a long-chain hydrocarbon residue of about 10 to 20 carbon atoms with ethylene oxide, for example, the condensation product of octadecyl alcohol and 25 to 30 mols of ethylene oxide or that of soya fatty acid and 30 mols of ethylene oxide or that of technical oleylamine and 15 mols of ethylene oxide or that of dodecylmercaptan and 12 mols of ethylene oxide. Amongst the anionic emulsifiers which may be employed, there may be mentioned: the sodium salt of dodecyl alcohol sulphuric acid ester, the sodium salt of dodecylbenzenesulphonic acid, the potassium or triethanolamine salt of oleic acid or of abietic acid or of mixtures of these acids, or the sodium salt of a petroleum-sulphonic acid. Possible cationic dispersing agents that can be used are quaternary ammonium compounds, for example, cetylpyridinium bromide or dihydroxyethylbenzyldodecylammonium chloride.

In order to manufacture dusting and scattering agents, it is possible to use, as solid carriers: talc, kaolin, bentonite, calcium carbonate, calcium phosphate, also charcoal, cork powder, wood flour and other materials of vegetable origin. It is also advantageous to manufacture the preparations in a granular form. The various forms in which the preparations can be used may, in the usual manner, be provided with additions of substances which improve the distribution, adhesion, rain resistance or penetrating power; as such substances fatty acids, resin, glue, casein or alginates may be mentioned.

The preparations according to the invention may be employed by themselves or together with usual pesticides, especially insecticides, acaricides, nematocides, bactericides or further fungicides and/ or herbicides.

The following Examples illustrate the invention:

EXAMPLE 1 C-n- C 11 A mixture of 38.6 g. 2n-propyl-5(6)-chloro-benzimidazole, 210 ml. of chloroform, 5 g. of MgO and 70 ml. of water is added into a 500 ml. sulfonation flask. The flask is then externally cooled and to the stirred content is added, dropwise, at a temperature range of 10 to 15 C. 23.2 g. of Methylthioformate. The reaction is slightly exothermic. When all the Methylthioformate is added, stirring is continued for 1% hours. The organic layer is then separated from the reaction mixture and dried over Na SO Then the solvent is distilled off and a dark oil remains which becomes solid; mp. 42 to 60. Analysis: N calc. 10.2%. N found: 10.42% (compound No. 1).

According to this Example the following compounds were prepared:

infested by rubbing conidia of the fungus against the wheat plants. The plants were left 12 days in the green house at 20 C. and then the infestation of the wheat with R R pdnlt/jhzgtiol'lg Erysiphe graminis was determined.

3 4 l Cyclopropyl CaH Oil 5 Concentra- Percent wheat H C5115 117-123 tion plants infested H CH3 80-84 applied, with Erysiphe Compound tested p.p.m. graminis DC EXAMPLE 2 5(6)-chloro-l-methylthiocarbonyl-2-n- 125 0-5 1 O propyl-benzimidazole. 3:? A 20% strength wetting powder is manufactured from compound No. 1 in the following manner: Control 20 g. of active substance are very finely ground in a pin mill together with 8 g. of fine precipitated silicon We clalmfl dioxide (commercially available under the name Zeosil) A benzlmldazole compound f the formula as Well as with 64 g. of bolus alba, 5.6 g. of a condensa- N tion product of 1 mol of p-tert. octylphenol with about 3 8 mols of ethylene oxide and 2.4 g. of sodium 2-hepta- C-R decyl-l-benzylimidazole-di-sulphonate. The powder thus R obtained can be worked up with water in any desired N amount, to give stable dispersions.

EXAMPLE 3 Fungicidal activity against Erysiphe on Cucumis sativa wherein R and R may be identical or different and are plants hydrogen, halogen, lower alkyl, nitro or trifiuoromethyl, Young plants of Cucumis sativus were sprayed with R3 is hydrogen. lower alkyl or cycloalkyl of 3 to 6 Garbo? suspensions containing 125, 250 and 500 p.p.1n. of 5(6)- and R4 15 lower or chloro-Z-n-propyl-l-methyl thiocarbonyl-Z-n-propyl-benz- Substltuted by i lower alkyl or or f imidazole (compound Na 1) These Suspensions were 2. The benzinndazole compound according to claim 1. prepared from a Wetting powder according to Example 2 l-phenylthrocarbonyl 2 cyclopropyl-5(6)-chlorobenzby dilution with water. After this spray had dried, the g g 1 d 1 1, plants were sprayed again with a suspension of spores of 1 f f q p accor mg to C mm Erysiphe. The plants were then left 8 days in a green- ,3; blocay 95 t I house at 23 C. Then the degree infestation by the fungus 1 th 1 F q Pg I accor mg 0 6 mm was evaluated and compared with the infestation of uny locar (my enzlml azo treated plants (control). The infestation with Erysiphe is References Cited given in percent leaf surface covered with a coating of mycelium. UNITED STATES PATENTS 40 3,652,580 3/1972 Janiak et al. 260309.2 Concentraiia .iiiissiitziii FOREIGN PATENTS Compound film. wan mycelium 1,803,728 6/1968 Germany 260309.2 5( hl 1 tp lthi -b l 2 France pmpyl'bemlmldame 52;; {2 OTHER REFERENCES 500 075 Conant et al., The Chemistry of Organic Compounds Control 3rd ed., p. 342, Macmillan Co., New York 1947.

Hunter et al., J. Chem. Soc. (London) 1941, pp. 7803 EXAMPLE 4 0 relied on.

Fungicidal activity against Erysiphe graminis DC on wheat plants Young wheat plants about 10 cm. high were sprayed in a greenhouse with suspensions containing 125, 250 and 500 ppm. of 5-chloro-1-methylthiocarbonyl-Z-n-propylbenzimidazole. These suspensions were prepared from a wetting powder according to Example 2 by dilution with water. After this spray has dried, the wheat plants were Oddo et al., Gazz. Chim. Ital., Vol. 62, pp. 1092-1100 (1932).

Patchornik et al., J. Amer. Chem. Soc., Vol. 79, pp. 6416-20 (1957).

NATALIE TROUSOF, Primary Examiner US. Cl. X.R. 71-72, 92; 424273 

1. A BENZIMIDAZOLE COMPOUND OF THE FORMULA 